Cool MateWhat is that vs What's that
When to use each in English, with meaning, register, and examples.
What is that
Top 1,000 (very common)
What's that
InformalTop 5,000 (fairly common)
Most formal: What is thatMost common: What is that
| What is that | What's that | |
|---|---|---|
| Pronunciation | 🇬🇧 //wɒt ɪz ðæt//🇺🇸 //wɑt ɪz ðæt// | 🇬🇧 //wɒts ðæt//🇺🇸 //wɑts ðæt// |
| Meaning | A question asking for identification of something. | A question asking about something you see or hear. |
| Example | Look at that strange object! What is that? | Look at that strange noise; what's that? |
| Register | Neutral | Informal |
| How common | Top 1,000 (very common) | Top 5,000 (fairly common) |
| Collocations | what is that noise, what is that thing, what is that smell | what's that sound?, what's that over there?, what's that doing? |
| Common mistakes | Omitting 'that' (e.g. saying 'What is?'), Using in overly formal contexts, Incorrect intonation in questioning | Used in formal situations where a more polite inquiry is needed., Confused with 'what is that', which is more formal. |
| Usage notes | Used to inquire about something unknown. Appropriate in most contexts, especially informal speech. | Used in casual conversation. Avoid in formal settings or written language, as it may seem too familiar. |
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Frequently asked questions: What is that vs What's that
What's the difference between What is that and What's that?
What is that: A question asking for identification of something. What's that: A question asking about something you see or hear.
Which is more formal: What is that and What's that?
What is that is the most formal of these.
Which is more common: What is that and What's that?
What is that is the most common in everyday English.
Can you show an example of each?
What is that: Look at that strange object! What is that? What's that: Look at that strange noise; what's that?
Can I use What is that and What's that interchangeably?
Not always. What is that and What's that are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.